Automatic circuit selector



May 9, 1939. F. KNEISLEY 2,157,417

AUTOMATIC CIRCUIT SELECTOR Filed Aug. 2, 1957 Fl E25; v

Patented May 9, 1939 PATENT OFFICE AUTOMATIC CIRCUIT SELECTOR Richard F. Kneisley, Toledo, Ohio, assignor to The American Floor Surfacing Machine Company, Toledo, Ohio, a corporation of Ohio Application August 2, 1937, Serial No. 156,877

2Claims.

This invention relates to automatic circuit selectors for multi-voltage motors, and is more particularly directed to an automatic circuit chan ing means by which the windings of the motor are properly connected with relation to the supply voltage. v

The invention is particularly useful in connection with motors which are adapted to run on 110 or 220 volts, and which are provided with 1|) two windings to be connected in parallel for 110 volt operation and in series for 220 volt operation. It is customary to provide a panel to which the ends 01 the windings are brought out and for the operator to make the proper connections in ac- 18 cordance with a circuit diagram furnished him before connecting the motor to the supply line. Howeventhere is the possibility that the operator might improperly make such connections and thereby subject the motor to excessive volt- The primary object of the' present invention is the provision of means to change automatically the connections of the windings of a multi-voltage motor before the line connection is made to 25 the windings.

Another object of the invention is the provision of a simple and eihcient, automatic means to connect thewindings of a multi-voltage motor in accordance with the voltage of the power sup- 30 ply to which the motor is to be connected.

Other objects of the invention will be apparent from the following detailed description, and from present invention; Figs. 2 and 3 are somewhat diagrammatic views, with parts broken away, of a relay and associated contacts which may be used to accomplish the change in connections, 40 the contacts being shown in their two operative positions, and Figs. 4 and 5 are diagrammatic representations of the motor windings in their two operating connections.

Referring to the drawing, the motor is desig- 45 nated l in Fig. l and is provided with two windings 8 and 9. The motor structure is the usual one which will permit operation on a double voltage supply, for instance on either 110 or 220 volts. As shown in Figs. 4 and 5, when the motor is con- 50 nected to the smaller voltage V, the windings should be connected in parallel, while, if the motor is to be operated from the larger voltage supply IV, the windings should be connected in series. Ordinarily, this circuit change from par- 65 allel to series is manually accomplished.

The ends of the motor winding 8 are brought out to connect with a stationary contact l2 and a movable contact it, while the ends of the motor winding 9 are brought out to connect with a stationary contact [3 and a movable contact i6. 5 Stationary contacts I6 and H are provided in opposition to the stationary contacts l2 and I3 and in the path of movement of the movable contacts l4 and 15. The stationary contacts I6 and I1 are electrically connected by a lead i8. 10

The motor is adapted to be supplied with current from a suitable source of electrical energy, such as line 20, which is connected to one side oi. a double pole motor switch through contacts 2| and 22. The switch is designated 23 and is connected through leads 24 and 25 to one side of each of the motor windings 8 and 9. The switch 23 may be of any suitable type and, if desired, may be constructed to stand normally in open position.

The present invention provides a means to connect the motor windings 8 and 9 in their proper relationship, depending on the supply. voltage, before the motor switch 23 isclosed, so

that at the time of closing this switch to operate 25 the motor, the windings will be in their proper connection. To accomplish this, a relay including a solenoid 26 is connected through leads 2'! and 28 to the contacts 2i and 22 of the double pole switch, and through these contacts directly 30 to the supply line. It will be seen that as soon as connection is made to the supply line, current will flow through the solenoid 26. The relay structure may take any suitable form, and, as shown in Figs. 2 and 3 may include a T'-shaped clapper element 30 on the ends of tlie crossmember of which the movable contacts I4 and It are carried. The clapper is hinged as at 32 to. a frame member 33, and at its far end is connected to a tension spring 34, so that it is biased to stand in the position shown in Fig. 2 with the movable contacts M and I5 in electrical connection with the stationary contacts I! and H3. The

winding of the solenoid 26 is such that if the down to the position shown in Fig. 3, so that the movable contacts now abut and electrically connect with the stationary contacts l6 and IT.

The change in position of the movable contacts I4 and i5 above-noted efiects a change from parallel to series connection of the motor windings. For the parallel connection, the circuit may be traced from contacts 2t and 22 through the motor switch 23, thence through lead 24 directly to one end of winding t and through stationary contact is and movable contact M to one end of winding 8. The other pole of the switch 23 at the same time is connected through lead 25 directly with the other end of winding a; and through stationary contact l2 and movable contact it with the other end of winding 9.

The series connection may be traced as follows: When the movable contacts i i and t5 abut against stationary contacts 06 and W, the circuit is from line contact 22 through one arm of the switch lead 26 directly to one end of winding 9, through winding 9 to movable contact 65, through stationary contact it and lead it to stationary contact ll, through movable contact t l toone end of winding 9, through winding to the direct connection with lead 25, through lead back to the other arm of switch 23, and hence to line contact 25.

It will be seen that the present invention provides a simple and eiilcient means to control the winding connections of a double voltage motor in use, since at the time connection was made between the movable contacts and stationary contacts to which the windings are connected, no current is flowing in the windings, so that there will be no pitting of the contacts by reason of breaking a circuit through which current is flow-' ing. Obviously, any suitable means may be substituted for the relay so long as it is actuated from the supply line ahead of the motor switch. This substitution may be made without departing from the invention as defined in the appended claims.

Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent, is:

l. The combination with an electric motor having two windings and adapted for operation on two line voltages, depending on whether the windings are connected in series or parallel, and a supply line for said motor, of an electromagnetically operated two position switch, a motor switch adapted to connect the motor to the line, means for connecting the motor windings to the two position switch for series or parallel operation, depending onthe position of said two position switch, means for connecting the windings of the motor to the motor switch through said two position switch, and means for connecting the electromagnet of said two position switch to the line. ahead of said motor switch whereby the .electromagnetically operated switch connects said 

